Pump



Paiented Nov. 24, 1942 Charles I. MacNeil, Glen Ridge, and Henry C. Nette, Rutherford, N. J., assignors to Bendix Aviation Corporation, "South Bend, Ind., a corporation of Delaware Application January 2, 1940, Serial No. 312,166 6 claims. (el. 10s-12s) This invention relates to pumps, and particularly to pumps for use in systems wherein a. reversal of the direction of fluid flow is occasionally but with the plane of section at right angles to that of Fig. 1;

desired, thereby necessitating a reversal of the direction of rotation of the pump.

It is common practice in the manufacturers design of many types of vpumps to vent the oil seal chamber where the shaft emerges from the pump housing and frequently to vent the bearing, to the intake or suction side of the pump. 'I'he reason for thisA practice is to relieve the oil seal and those surfaces of the pump surrounding the bearings, of the necessity of restraining high pressure.

A common practice of pump manufactures and designers toobtainv this result, isvto design one housing of the pump so that it may be reversible by removing the housing and rotating it 180, thereby changing the location of the oil passages inside the pump in respect to the pressure passages in such a manner that the above mentioned oil chambers and bearing cavities are vented to the intake side of the pump. e l In-view of the desirability that pumps be so manufactured that the necessity, of dissembling the pumps in order to obtain the desired results be eliminated, it `has been proposed to achieve the desired results by a system of passages and plugs which would be interchanged by a mechanic when changing the, pump from one rotation to the other. Y

By the present invention there is provided a valve arrangement which automatically transfers the vent passages to the intake side of the pump :egardless of rotation. While it is possible that )ther procedures may have been adopted by bodied in a housing having two main sections Il.l

Jthers this is to the best of our knowledge a new g .ing are for the purpose of illustration only, and

are not designed as a denition of the limits o f the invention, reference being had to the appended claims for this purpose.

In the drawing;

Fig. 3 is a transverse sectional view along the line 3-3 of Fig. 1; and

Fig. 4 is a transverse sectional View along the line 4-5 of Fig. 2.

'I'he pump is shown in the drawing as emand I2`labutting the opposite surfaces of an intermediate plate I3, the three elements II, l2, and I3 being retained in assembled relationship by suitable screw bolts, I4 and additional retaining the driving element of a prime mover, notshown. The drive member I9 has-a socketed portion 23 iny which are radially disposed pins 24 serving to transmitthe drive to the pump shaft 26 withwhich is integrated the pump rotor 21 herein shown in. the form df a gearadapted to mesh with a corresponding gear 28 (Fig. 2) the latter having' cylindrical extensions 3i and 32 integral therewith and journaled in the bearing elements 3S and 3l, respectively, of the pump. When the drive shaft is rotating in a clockwise direction as viewed in Fig. 3 the gear elements 2l and' 2?: cooperate to pump fluid entering chamber il and 'deliver it to the discharge conduit by way of the outlet or pressure chamber 42 While a reversal in the directionof rotation causes chamber i2 to become the suction side and il the pressure or outlet chamber. The novel means whereby the oil seal containing chamber 5i (Fig. l) is4 auto- Fig. 1 is a longitudinal sectional View of a device embodying the invention;

Fig. 2 is a second longitudinal sectional View matically vented to the suction side of the pump regardless of thedirection of rotation-that is,

regardless of whether the side 4l or the side d2 is co-temporaneously serving as the suction or intake side of the pump-is shown in Fig. 4 as including a cylindrical slide valve 52 operating in an obliquely disposed cylindrical bore 54 formed in the bearing element 3l, the valve element 52 having circumferential grooves 61 and 66 whichin theposition of the valve indicated in Fig. 4

are in communication with longitudinally extendj ing passages 68 and 69, respectively, the former of which is open to the chamber 42| and the latterA lto the chamber 4|. In this position of valve the two ports il and 'l2 (shown as extending ver-4 tically in Fig. 4, but actually running diagonally from the chambers at the ends of the rotor bearings 30 and 32, respectively) are in communica-- tion with the single circumferential groove at Il and are therefore in positionsuch that the oil sealing chamber as well as the bearing cavities 83 and 84 are vented to the intake chamber 4| (this being the intake chamber in the direction of rotation in which the valve 52 occupiesthe position shown in Fig. 4) the path of communication from chamber 5i being by rway of radial passage lll,` (Fig. l) the interior 82 of the rotor bearing element 30, the end chamber 83, the port 1 |,y the circumferential groove 66, and the longii tudinal passage 69. This condition occurs until the direction of rotation is reversed and there is a consequent reversal of the pressure conditions in the chambers 4| and 42-'that is, the chamber 4I now becomes the pressure or outlet chamber and the chamber 42, the suction or intake chamber. When this reversal occurs the resulting pressure change is effective upon the end surfaces of the 'valve 52 to shift the latter in its cylinder 54 from the position indicated in Fig. 4 to the opposite extreme position whereupon the circumferential groove 61 now comes into communication with the port 1| thereby establishing a pressure reliev- 25 ing path from the/oil seal chamber 5| to the chamber 42 which (rather than the chamber 4|) is now the intake or suction side of the pump; the new path from the chamber 5| being by way of passages 8i, B2, 83, 1|, 61, and 68 to the cham- 30 `ber 42.

There is thus provided an automatically acting oil seal pressure relieving means functioning to prevent the development of unduly high pressure in the sealing chamber 5i regardless of the direction of rotation Aof the pump.

What I claim is:

l. in a pump having a drive shaft and a pair of chambers one of which acts as the suction chamber during rotation of the drive shaft in one direction and as the pressure or outlet chamber during rotation of the drive shaft in the opposite direction, an oil seal containing chamber surrounding the pump rotor drive shaft, and means for automatically establishing and maintaining communication between said oil seal containing chamber and said rst-named chamber during rotation of the drive shaft in one direction, said means acting automatically to interrupt .said communication in response to' reversal in the direction of rotation of the drive shaft.

2. In a pump having a drive shaft and a pair of chambers one of which acts as the suction chamber during rotation of the drive 'shaft in one direction and as the pressure or outlet chamber during rotation of (the drive shaft in the oppomte direction, bearing cavities adjacent the pump bearings, and means for automatically establishing and maintaining communication between said bearing cavities and said first-named chamber during rotation of the drive shaft in one direction, said means acting automatically to interrupt said communication in response to reversal in the direction of rotation of the drive shaft.

r asoaccc' 3. In a pump having a drive shaft and a pair of chambers one of which acts as lthe suction chamber during rotation of the drive shaft in one `direction and as the pressure or outlet chamber during rotation in the opposite direction, a sec-y f ond shaft parallel to said drive shaft, an oil seal hollow hubs to control the venting of said bearing cavities, said means including a valve movable from one extreme position to the other, and means operative in responsev to reversal of the direction of rotation of said gears to vary the pressure acting upon said valve and thereby shift said valve in its relationship to said cavities, to direct fluid flow from said cavities to one side of the pump forone direction of rotation, and to the other side of the pump during rotation in the opposite direction.

5. In a pump having a casing including a cover plate on one side and a drive-shaft-receiving section on the othergsaid drive-shaft-receiving section including` a sealing chamber having sealing means therein, conduits leading from said casing, one of said conduits being the inlet during clockwise rotation of said drive-shaft, the

other being the inlet during counterclockwise rotation of said drive-shaft, and means loperative independently of said cover Aplatefor causing a discharge of iluid'from said Sealing chamber to the particular conduit constituting, at any given time, the inlet conduit.

6. In a hydraulic pump, a housing formed with a pump chamber having fluid openings communicating respectively with said chamberv at diametrically opposite si es, each of said openings being adapted to functio as a pump inlet or outlet, meshing pump gears, rotatably disposed in said chamber and adapted for vrotation in either a forward or reverse direction, drive shaft means for said gears including a sealing chamber having sealing means therein, a bore in said housing, a conduit connecting said sealing chamber and saidbore, a passageway leading from each fluid opening to a respective end of said bore and a fluid pressure actuated member slidably disposed in said bore and selectively operable for causing a discharge of fluid from said sealing chamber to the particular fluid opening constitut-v ing at any given time the pump inlet opening regardless of the direction of rotation of said gears.

CHARLES I. MACN'EIL. HENRY C. NE'ITE. 

